kdesvn is yet another client for subversion. But it uses native KDE API instead of a extra lib like GAMBAS and it is using the native subversion delevelopment API instead of just parsing the output of the commandline tool like most other clients do. It tries to setup a look and feel like the standard filemanager of KDE and is integrated into it via KPart.
The base C++ interface to subversion I took from the (real great) tool Rapidsvn (see http://rapidsvn.tigris.org/) with some modifcations and fixes.